The NF.Mk XVII was the first version of the de Havilland Mosquito to be equipped with centimetric radar, and was producing by converting 100 NF.Mk IIs to carry the American produced SCR720/729 radar (soon given the RAF designation A.I. Mk X). The modification involved fitting a “bullnose” universal radome in the nose to carry the radar scanner, and fitting four 20mm cannon in a ventral tray.
The first aircraft to be so converted, serial number DZ659, made its first flight in the new configuration in March 1943. It was the first of 100 Mk IIs to be converted by Marshalls Flying Services (serial numbers HK195, HK237-265 (29 aircraft); HK278-327 (50 aircraft) and HK344-362 (19 aircraft)).
The NF.Mk XVII entered service with No.24 Squadron on 4 January 1944. Its first victory came on 20 February, when Pilot Officer J. R. Brockbank in HK285/G shot down a Ju 188 during a raid over London. Eventually six squadrons would use the Mk XVII, which proved to be a very effective night fighter. It would also score a number of successes against the V-1 flying bomb. Amongst the efforts made to counter the V-1 was the fitting of rear-looking radar in a Perspex tail cone to HK 324/G. The Mk XVII was followed into service by the Mk XIX, which could be equipped with either the A.I. Mk VIII or Mk X.
Engine: Two Merlin 21 or 23 with long nacelles
Span: 54ft 2in
Length: 40ft 6in
Height: 12ft 6in
Empty weight: 13,224lb
Maximum weight: 20,393lb
Maximum speed: 370mph
Cruising speed: 255mph
Armament: Four 20mm Hispano Mk III cannon in ventral tray
Bomb load: 1,000lb